关闭按钮的WKWebview弹出窗口？

import UIKit
import WebKit

class ViewController: UIViewController, WKUIDelegate, WKNavigationDelegate {
    
    var webView: WKWebView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let webConfiguration = WKWebViewConfiguration()
        webView = WKWebView(frame: view.bounds, configuration: webConfiguration)
        webView.uiDelegate = self
        webView.navigationDelegate = self
        view.addSubview(webView)
        
        let url = URL(string: "https://example.com")
        let request = URLRequest(url: url!)
        webView.load(request)
    }
    
    // WKNavigationDelegate method to handle new window requests
    func webView(_ webView: WKWebView, createWebViewWith configuration: WKWebViewConfiguration, for navigationAction: WKNavigationAction, windowFeatures: WKWindowFeatures) -> WKWebView? {
        if navigationAction.targetFrame == nil {
            let newWebView = WKWebView(frame: view.bounds, configuration: configuration)
            newWebView.uiDelegate = self
            newWebView.navigationDelegate = self
            view.addSubview(newWebView)
            
            let closeButton = UIButton(frame: CGRect(x: 10, y: 10, width: 50, height: 50))
            closeButton.setTitle("Close", for: .normal)
            closeButton.addTarget(self, action: #selector(closeButtonTapped), for: .touchUpInside)
            newWebView.addSubview(closeButton)
            
            return newWebView
        }
        return nil
    }
    
    @objc func closeButtonTapped() {
        webView.close()
    }
}